Field
Aspects of the present disclosure relate generally to wireless communication and, more particularly, to antenna selection in a wireless terminal with two radios.
Background
A wireless terminal, for example, a mobile phone, may include multiple radios and multiple antennas. The communication channels to and from the antennas can vary greatly. For example, when a user holds a mobile phone, one antenna may be blocked by the user's hand while another antenna is substantially open. When the mobile phone uses the blocked antenna for communications, there may be, for example, a 10-30 dB attenuation relative to when the unblocked antenna is used. Thus, a wireless terminal may improve performance by switching the antenna that is used away from a blocked antenna.
A wireless terminal may also provide concurrent communications for two protocols, for example, in dual-SIM, dual-active (DSDA) or simultaneous voice and long term evolution (SVLTE) systems. Each of the protocols may be processed by a particular one of the radios. The communication channels for the protocols may differ (for example, depending on the distance to the respective base stations) in such a way that one allocation of antennas provides reliable communication for both protocols but when the antennas are switched, reliable communication for one of the protocols is not achieved.
Antenna selection can be performed by detecting that performance of a radio is degraded and then switching antennas. However, switching to a different antenna may not result in improved performance. Additionally, communications to the wireless terminal are interrupted when the antennas are switched.